ST. LOUIS (AP) — St. Louis Fire Chief Dennis Jenkerson says a boiler that killed one person when it exploded at a box company in St. Louis flew about 500 feet before crashing through the roof of a nearby laundry business, killing two more.

The boiler exploded Monday morning at the Loy-Lange Box Co. Four other people were injured and at least two are in critical condition.

A third person at Faultless Healthcare Linen was pinned under the boiler but fire department responders were able to free that victim.

Jenkerson says the boiler was a cast iron cylinder about 8 or 9 feet long and 4 feet in diameter, weighing about 1½ tons. He says it was about the size of a van.

A piece of pipe about 8 feet long pierced the roof of the nearby Pioneer Industrial Corp., but no one was injured there.